The proposal outlines experiments designed to test the proposition that cells can be protected from HIV infection by programming them to synthesize protective macromolecules. We term this,intracellular immunization. Our major hope is that the expression of anti-sense RNA's will protect cells by either preventing total reverse transcription of the viral genome or expression of integrated viral genomes. Another possibility is that a small sense RNA representing the 5' end of viral RNA will be effective because it will compete with tat-responsive sequence element, TAR. Another possibility is that viral proteins, particularly the glycoprotein will be inhibitory. This is conceptually quite separate from the other parts of this grant but brings to the consortium particular technical strengths and balances and approach to protection of the population against HIV.